Electric nipper-type dry shaver



3 Sheets-Sheet 1 Filed May 2l, 1959 drronlvys Nov. 27, 1962 K. BUERLE 3,065,541

ELECTRIC NIPPER-TYPE DRY sHAVER Filed May 21. v1959 5 sheets-sheet 2 Tron/V575' `when cutting, in the same plane.

United States atene 3,065,541 ELECTRIC NIPPER-TYPE DRY SHAVER Kurt Buerle, Unotweg 16, Sehramberg-Sulgen, Baden-Wurttemberg, Germany Filed May 21, 1959, Ser. No. 814,709 Claims priority, application Germany May 23, 1958 5 Claims. (Cl. Sil-42) The invention relates to an electric dry shaver. Most conventional devices of this kind operate on the principle of a shearing operation. It is also known, however, that a different principle may be employed in dry Shavers, i.e. that of clipping as by a pair of nippers. In this case, the cutting edges of one or more pairs of knives movable towards each other like pincers are outermost and, at least In this way, it is possible to avoid the clearance between skin and cutting means that is necessitated in conventional Shavers with shearing head by the presence of a shear plate or other thin sheet of material serving as a shearing blade, so that the hairs can be cut olf close to the surface of the skin.

Despite this important advantage over Shavers with strict shearing operation, dry Shavers with pincer-like clipping operation have not yet appeared on the market. There are various reasons for this. `If the principle outlined above is applied to `devices having only one pair of knives cooperating pincer-fashion, the result is an appliance of simple design and manufacture, but the shaving process is too slow. If the number of pairs of knives is increased for greater effectiveness, then the requirement that the cutting edges of the two jaws must meet very accurately in the act of cutting without deviating upward or downward presents considerable difficulty. In known devices having one stationary and one cutter, the latter movable cutter is slidably mounted under spring action in the stationary cutter to achieve this accurate meeting of the cutting edges. If clearance between the two cutters is eliminated by means of a comparatively powerful spring, or if the slide connection allows virtually no play, there will in either case be severe friction and hence much waste of applied power. The customary comparatively low-power `driving means such as electromagnets with oscillating armatures, small electric motors and the like, are therefore unable to develop enough force for the shaving operation proper, i.e. the severing of the hairs.

Another circumstance contributes to this difficulty. In shavers operating on the shearing principle, the holes or slits in the stationary and the moving knives may be so distributed that, at least to some extent, the knives will act lsuccessively throughout the cutting stroke. In this way, the force required is diminished to the extent that the usual power systems are adequate. In applying the principle of clipping as by pincers, on the other hand, all blades act at the same instant, so that it is not possible to distribute the power requirement. v

The object of the invention is to overcome these dif- `culties that militate against the use of the principle of clipping the hairs off pincer-fashion. It consists, rstly, in that the shaver comprises two meshing cutters of equal height having transverse teeth or blade members with cutting edges on both sides; one of these cutters, a stationary one, is fixed to the surface of a rigid part of the housing, while the other, a longitudinally movable cutter, is iixed to the surfacein the same plane as the surface of the rigid housing part-of a frame part attached to the xed part of the housing 'so as to be restricted reciprocable in cutting `direction only, so that the movable cutter is able to reciprocate without friction independently of the stationary cutter, and the cutting edges of both arrays of blade members are always opposed at exactly the same height.

The two cutters slide neither on tracks of their own nor 3,065,541 Patented Nov. 27, 1952 in each other; rather, the movable cutter, which is free to move only in cutting direction, reciprocates frictionlessly to and fro.

Friction at points of bearing is eliminated because the stationary cutter of course cannot generate friction and because the longitudinally movable cutter is attached to two leaf springs connected with the housing, the springs forming with the movable cutter a substantially parallelograrnmatic linkage which springs holding the cutter freely suspended and Without friction in opposition to the stationary cutter while permitting reciprocating movements of the movable cutter exclusively in the cutting directions.

A simple design solution, at the same time permitting accurate and permanent adjustment of the cutting edges relative to each other, consists in that the movable cutting member is lixedly but detachably mounted on the flat top of a |bridge member fastened to the leaf springs, and in that the reciprocable linkage consisting of the leaf springs, the bridge member and the movable cutter is mounted, together with the armature of an electromagnet controlling it, in a rigid frame that likewise bears the stationary cutter and is detachably fastened bodily to the housing, prefer.- ably by means of rubber sleeves and screws. This construction has the additional advantage in manufacture that those parts of the appliance that require accurate positioning can be produced as separate components and mounted, Without special adjustment, on the coplanar top surfaces of the bridge member and the supporting frame.

The same purpose, and that of uniform adjustment of the armature relative to the cutting edges without play, is served if, in furuther accordance with the invention, the bridge member is fitted with laterally adjustable hardened spring transmission members, preferably attached by means of pins with eccentric circumferential groove, which cooperate elastically, but without play, with a lever connected to the armature of an electromagnet and pivoted in the supporting frame.

Since the lever transmitting the force of the magnet to the movable shaving cutter is mounted in the same sup` porting frame as the cutters, the relative position of these parts remains completely unaltered in operation.

As mentioned above, the principle applied in Vthe apparatus of the invention, i.e. that of clipping the hairs as by nippers, requires considerable force in the act of cutting., In order to develop this force without having to use more powerful driving means, the arms of the controlling lever, subject to the action of two springs reacting against the leaf springs and tending to hold it in a centered position, are so proportioned that the shorter arm, i.e. the one cooperating with the transmission members, executes reciprocations of only about 0.2 to 0.3 millimeter.

The device according to the invention will now be more fully described with reference to the accompanying drawing, but it should be understood that the same is given merely byvway of illustration and not of limitation and that many changes in the details may be made without departing from the spirit of the invention.

In the drawing: j

FIG. l shows a top view of an embodiment of the invention with cover part removed, in partial longitudinal section;

FIG. 2 shows a sectional side View of the same;

FIG. 3 shows a longitudinal section of the frame assembly;

FIG. 4 is a top View, in partial section, of the moving shaver cutter and its suspension means;

FIG. 5 is a similiar view of th stationary cutter;

FIG. 6 is a partial side view in the direction of the arrow VI in FIG. 3;

FIG. 7 is a side view of the movable cutter;

FIG. 8 is a side View of the stationary cutter;

ing, said stationary cutter means comprising an elongated -first carrier member and a -rst array of spacedapart blade members extending from said housing and defining a cutting surface; movable cutter means spaced from said stationary cutter means within said housing, said movable cutter means comprising an elongated second carrier member and a second array of blade members interleaved with clearance between the blade members of said first array and terminating at said cutting surface for reciprocating motion parallel thereto relative to said first array; a parallel-motion linkage including resilient means supporting said movable cutter means with freedom `from frictional engagement with said stationary cutter means for reciprocating displacement of said second array alono said surface and substantially only in the plane of said second array; and motive-power means within said housing for reciprocating said rnovable cutter means, said resilient means constituting a pair of substantially inextensible elongated resilient arms of said linkage, secured to said second carrier member at longitudinally opposite extremities thereof and to said housing at spaced locations.

4. In a dry shaver, in combination, a housing; stationary cutter' means rigidly supported within said housing, said stationary cutter means comprising an elongated rst carrier member and a iirst array `of spaced-apart blade members extending from said housing and defining a cutting surface; movable cutter means spaced from said stationary cutter means within said housing, said movable cutter means comprising an elongated second carrier member and a second array of blade members interleaved with clearance between the blade members of said first array and terminating at said cutting surface for reciprocating motion parallel' thereto relative to said first array; a parallelogramrnatic linkage including resilient means supporting said movable cutter means with freedom from frictional engagement with said stationary cutter means for reciprocating displacement of said second array along said surface and substantially only in the plane of said second array; and motive-power means Within said housing for reciprocatng said movable cutter means, said resilient means constituting a pair of substantially inextensible leaf springs forming ar-ms of said linkage, said leaf springs being secured to said second carrier member at longitudinally opposite extremities thereof and to said housing at spaced locations and being flexible substantially only in directions of reciprocation of said movable cutter means.

5. in a dry shaver, in combination, a housing; stationary tirst cutter means rigidly supported within said housing, said stationary cutter means comprising an elongated Ifirst carrier member and a -first array of spacedapart blade members extending from said housing and defining a cutting surface; movable cutter means spaced from said stationary cutter means within said housing, said movable cutter means comprising an elongated second carrier member and a second array of blade members interleaved with clearance between the blade members of said first array and terminating at said cutting surface for reciprocating motion parallel thereto relative to said tirst array; a parallel-motion linkage including resilient means detachably engaging said movable cutter means and oatingly supporting said movable cutter means with `freedom from frictional engagement with said stationary cutter means for reciprocating displacement of said second array along said surface and substantially only in the plane of said second array; and motive-power means within said housing for reciprocating said 'movable cutter means, said resilient means constituting a pair of substantially inextensible leaf springs forming arms of said linkage, said leaf springs being secured to said second carrier member at longitudinally opposite extremities thereof and to said housing at spaced locations and being flexible substantially only in directions of reciprocation of said movable cutter means.

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